/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/**
 * Project  : IQQ_V2.1
 * Package  : iqq.app.event
 * File     : IMEventHandlerProxy.java
 * Author   : solosky < solosky772@qq.com >
 * Created  : 2013-3-16
 * License  : Apache License 2.0 
 */
package iqq.app.event;

import iqq.app.core.IMContext;
import iqq.app.core.IMException;
import iqq.app.core.IMService;
import iqq.app.service.IMEventService;

import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;

import org.apache.log4j.Logger;

/**
 * 使用这个类简化事件的注册，分发 只需在被代理的类使用@IMEventHandler注解需要处理的事件类型即可
 * 
 * @author solosky <solosky772@qq.com>
 */
public class IMEventHandlerProxy implements IMEventListener {
    private static final Logger LOG = Logger.getLogger(IMEventHandlerProxy.class);
    private static Map<Object, IMEventHandlerProxy> REGISTRY = new HashMap<Object, IMEventHandlerProxy>();
    private Object proxyObject;
    private Map<IMEventType, Method> methodMap;
    private IMContext imContext;

    private IMEventHandlerProxy(Object proxyObject, IMContext imContext) {
        this.proxyObject = proxyObject;
        this.imContext = imContext;
        this.methodMap = new HashMap<IMEventType, Method>();
        for (Method m : proxyObject.getClass().getDeclaredMethods()) {
            if (m.isAnnotationPresent(IMEventHandler.class)) {
                IMEventHandler handler = m.getAnnotation(IMEventHandler.class);
                this.methodMap.put(handler.value(), m);
                if (!m.isAccessible()) {
                    m.setAccessible(true);
                }
            }
        }
    }

    public void onIMEvent(IMEvent imEvent) throws IMException {
        Method m = methodMap.get(imEvent.getType());
        if (m != null) {
            try {
                m.invoke(proxyObject, imEvent);
            } catch (Throwable e) {
                LOG.warn("invoke IMEventHandler Error!! proxyObject=" + proxyObject + ", method=" + m.getName(), e);
            }
        } else {
            LOG.warn("IMEventHandler Not Found!! imEvent = " + imEvent);
        }
    }

    public void register() {
        IMEventService eventHub = imContext.getSerivce(IMService.Type.EVENT);
        eventHub.register(this.methodMap.keySet().toArray(new IMEventType[0]), this);
    }

    public void unregister() {
        IMEventService eventHub = imContext.getSerivce(IMService.Type.EVENT);
        eventHub.unregister(this);
    }

    public static void register(Object proxyObject, IMContext imContext) {
        if (!REGISTRY.containsKey(proxyObject)) {
            IMEventHandlerProxy proxy = new IMEventHandlerProxy(proxyObject, imContext);
            proxy.register();
            REGISTRY.put(proxyObject, proxy);
        }
    }

    public static void unregister(Object proxyObject) {
        IMEventHandlerProxy proxy = REGISTRY.get(proxyObject);
        if (proxy != null) {
            proxy.unregister();
        } else {
            LOG.warn("Not found proxyObject from local registry!!!" + proxyObject);
        }
    }
}
